Biomedical subjects

David H Oram

Publications and source records attributed to David H Oram.

3 recordsLinked to original sources

PubMed2006

Basic surgical skills.

A team approach is essential to the practice of successful surgery. Good surgery begins before any incision is made with consideration of the type of equipment needed and the incision to be used to ensure optimum access. Although the repertoire of tools available to the surgeon has increased, the attainment of safe and efficient surgical technique still depends on a comprehensive knowledge of the basic surgical skills outlined in this chapter. These include proficiency in knot tying, instrument handling, suturing, haemostasis and tissue dissection. Surgery should 'flow', using the simplest and safest way to achieve the operative goal. As the duration of training shortens, the importance of teaching good surgical technique by example and direct supervision has never been greater.

Clinical Competence↗

PubMed2005

Diagnostic performance of nanoparticle-enhanced magnetic resonance imaging in the diagnosis of lymph node metastases in patients with endometrial and cervical cancer.

PURPOSE: Lymph node metastases affect management and prognosis of patients with gynecologic malignancies. Preoperative nodal assessment with computed tomography or magnetic resonance imaging (MRI) is inaccurate. A new lymph node-specific contrast agent, ferumoxtran-10, composed of ultrasmall particles of iron oxide (USPIO), may enhance the detection of lymph node metastases independent of node size. Our aim was to compare the diagnostic performance of MRI with USPIO against standard size criteria. METHODS: Forty-four patients with endometrial (n = 15) or cervical (n = 29) cancer were included. MRI was performed before and after administration of USPIO. Two independent observers viewed the MR images before lymph node sampling. Lymph node metastases were predicted using size criteria and USPIO criteria. Lymph node sampling was performed in all patients. RESULTS: Lymph node sampling provided 768 pelvic or para-aortic nodes for pathology, of which 335 were correlated on MRI; 17 malignant nodes were found in 11 of 44 patients (25%). On a node-by-node basis, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) by size criteria were 29%*, 99%, 56%, and 96%, and by USPIO criteria (reader 1/reader 2) were 93%/82%* (*P = .008/.004), 97%/97%, 61%/59%, and 100%/99%, respectively (where [*] indicates the statistical difference of P = x/x between the two results marked by the asterisk). On a patient-by-patient basis, sensitivity, specificity, PPV, and NPV by size criteria were 27%*, 94%, 60%, and 79%, and by USPIO criteria (reader 1/reader 2) were 100%/91%* (*P = .031/.06), 94%/87%, 82%/71%, and 100%/96%, respectively. The kappa statistic was 0.93. CONCLUSION: Lymph node characterization with USPIO increases the sensitivity of MRI in the prediction of lymph node metastases, with no loss of specificity. This may greatly improve preoperative treatment planning.

Adult↗

PubMed2003

Calculation of the risk of ovarian cancer from serial CA-125 values for preclinical detection in postmenopausal women.

PURPOSE: Previous studies of CA-125 levels from screening trials for ovarian cancer have indicated that serial CA-125 levels may identify cases better than a fixed CA-125 cutoff. We conducted a study to assess the screening performance of the risk of ovarian cancer calculation based on serial CA-125 levels from prospectively collected serum samples compared with a fixed CA-125 cutoff. PATIENTS AND METHODS: The calculation was applied to data from a prospective trial of screening for ovarian cancer involving 22,000 postmenopausal women older than 45 years. The analysis was performed using 33,621 CA-125 results from 9,233 women for whom two or more serial samples were available. All serum samples from the patients with ovarian cancer were obtained before clinical detection. Sensitivity and specificity levels for preclinical detection of index cancers were calculated for various cutoffs for the risk and a single CA-125 measurement, and receiver operator curves were constructed. RESULTS: The risk calculation significantly improved the area under the curve from 84% to 93% compared with a fixed cutoff for CA-125 (P =.01). For a target specificity of 98%, the risk achieved a sensitivity of 86% for preclinical detection of ovarian cancer, whereas CA-125 achieved a sensitivity of 62%. The estimates of performance are unbiased, because the risk calculation was derived independent of the data from this trial. CONCLUSION: These results provide the first evidence that preclinical detection of ovarian cancer using serial CA-125 levels interpreted with the risk calculation significantly improves screening performance compared with a fixed cutoff for CA-125. The results justify the incorporation of the risk calculation in a prospective, randomized, controlled trial.

Area Under Curve↗